Multi-ancestry genome-wide association study of gestational diabetes mellitus highlights genetic links with type 2 diabetes.

Gestational diabetes mellitus (GDM) is associated with increased risk of pregnancy complications and adverse perinatal outcomes. GDM often reoccurs and is associated with increased risk of subsequent diagnosis of type 2 diabetes (T2D). To improve our understanding of the aetiological factors and molecular processes driving the occurrence of GDM, including the extent to which these overlap with T2D pathophysiology, the GENetics of Diabetes In Pregnancy Consortium assembled genome-wide association studies of diverse ancestry in a total of 5485 women with GDM and 347 856 without GDM. Through multi-ancestry meta-analysis, we identified five loci with genome-wide significant association (P < 5 × 10-8) with GDM, mapping to/near MTNR1B (P = 4.3 × 10-54), TCF7L2 (P = 4.0 × 10-16), CDKAL1 (P = 1.6 × 10-14), CDKN2A-CDKN2B (P = 4.1 × 10-9) and HKDC1 (P = 2.9 × 10-8). Multiple lines of evidence pointed to the shared pathophysiology of GDM and T2D: (i) four of the five GDM loci (not HKDC1) have been previously reported at genome-wide significance for T2D; (ii) significant enrichment for associations with GDM at previously reported T2D loci; (iii) strong genetic correlation between GDM and T2D and (iv) enrichment of GDM associations mapping to genomic annotations in diabetes-relevant tissues and transcription factor binding sites. Mendelian randomization analyses demonstrated significant causal association (5% false discovery rate) of higher body mass index on increased GDM risk. Our results provide support for the hypothesis that GDM and T2D are part of the same underlying pathology but that, as exemplified by the HKDC1 locus, there are genetic determinants of GDM that are specific to glucose regulation in pregnancy.

FABP4 and I-FABP Levels in Pregnant Women Are Associated with Body Mass Index but Not Gestational Diabetes.

Objectives: Gestational diabetes mellitus (GDM) is glucose intolerance detected initially during pregnancy. GDM poses an increased risk for the development of diabetes later in life. Fatty acid-binding protein 4 (FABP4) is a regulator of lipid metabolism and is associated with obesity, insulin resistance, and type 2 diabetes. Increased level of intestinal fatty acid-binding protein (I-FABP) may indicate impaired intestinal permeability, which may be an important contributor to the pathogenesis of type 1 diabetes and GDM. We aimed to compare FABP4 and I-FABP levels in pregnant women with GDM and in healthy pregnant controls, taking into consideration their prepregnancy body mass index (BMI), past exposures to enteroviruses (EV), and adipokine and cytokine levels, which have been shown to decrease insulin sensitivity. Material and Methods. Forty patients with GDM (median age 30.5) and 40 pregnant healthy controls (median age 31.1) were divided on the basis of their prepregnancy BMI into two groups: normal weight (BMI < 25, n = 20) and overweight (BMI ≥ 25, n = 20). FABP4 and I-FABP were measured from serum samples using commercial ELISA kits. Results: FABP4 and I-FABP levels did not differ between women with GDM and healthy pregnant controls (p > 0.05 for both comparisons). However, both levels were associated with BMI (p < 0.001 for both comparisons). Median I-FABP level was the highest in healthy controls with lower BMI (<25) (p = 0.0009). FABP4 levels correlated with BMI and C-peptide values in both groups (p < 0.001). Anti-EV antibody levels did not correlate with FABP4 or I-FABP levels. FABP4 and adiponectin levels were negatively correlated in controls (r = -0.61, p = 0.0009), while I-FABP correlated positively with adiponectin (r = 0.58, p = 0.04) and resistin (r = 0.67, p = 0.04) levels in the GDM group. Conclusion: FABP4 and I-FABP levels were not dependent on the diagnosis of GDM, but rather on BMI. The correlation of I-FABP with adiponectin and resistin levels in women with GDM may suggests the importance of lipid metabolism in GDM-associated changes in intestinal permeability.

Plasma cytokines during pregnancy provide insight into the risk of diabetes in the gestational diabetes risk group.

AIMS/INTRODUCTION: Gestational diabetes (GDM) is characterized by low-grade systemic inflammation, which manifests as changes in the levels of cytokines in the blood. We aimed to investigate plasma immune mediators during gestational weeks 23-28 in 213 women at risk for GDM, and to find associations between GDM and its complications. MATERIALS AND METHODS: We quantified the levels of adipokines: adiponectin, leptin, plasminogen activator inhibitor-1 and resistin; chemokines: C-C motif chemokine ligand 2 (CCL2), CCL4, C-X-C motif chemokine ligand 8 (CXCL8) and CXCL10; and cytokines: granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin (IL)-1ß, soluble (s)IL-1RI, IL-2, sIL-2Ra, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12(p70), IL-13, IL-15, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-27, transforming growth factor (TGF)-ß1, TGF-ß2, TGF-ß3, tumor necrosis factor-α and soluble tumor necrosis factor receptor 2 using the Milliplex®MAP Magnetic Bead assay on Luminex®200™, and compared the results with clinical data from pregnancy and post-partum follow up. RESULTS: Lower levels of adiponectin and higher levels of CCL2 (Wilcoxon test, P = 3.4E-03 and P = 0.03, respectively) were found in women with GDM. IL-27 levels were associated with lower odds of GDM (adjusted logistic regression 0.90, P = 2.4E-03), and showed a risk association with glutamic acid decarboxylase autoantibody positivity (adjusted odds ratio 1.13, P = 2.8E-03). Similarly, higher IL-22 levels increased the odds of glutamic acid decarboxylase autoantibody positivity (adjusted odds ratio 4.23, P = 0.04). TGF-ß1 was associated with post-partum fasting glucose levels, and CCL4 with post-partum C-peptide levels (linear regression, P = 0.04 and P = 0.01, respectively). Women who developed pregnancy complications had higher levels of CXCL10 and CCL4 (linear regression, P = 7.0E-04 and P = 0.01, respectively). CONCLUSIONS: Plasma adiponectin and CCL2 concentrations distinguish women with GDM. IL-27 and IL-22 levels might select women with an autoimmune reaction, whereas increased TGF-ß1 and CCL4 are associated with post-partum glucose and insulin metabolism.

Maternal breast milk microbiota and immune markers in relation to subsequent development of celiac disease in offspring.

The potential impact of the composition of maternal breast milk is poorly known in children who develop celiac disease (CD). The aim of our study was to compare the microbiota composition and the concentrations of immune markers in breast milk from mothers whose offspring carried the genetic predisposition to CD, and whether they did or did not develop CD during follow-up for the first 3 years of life. Maternal breast milk samples [CD children (n = 6) and healthy children (n = 18)] were collected 3 months after delivery. Enzyme-linked immunosorbent assays were used to measure TGF-ß1, TGF-ß2, sIgA, MFG-E8 and sCD14. For microbiota analysis, next generation (Illumina) sequencing, real-time PCR and denaturing gradient gel electrophoresis were used. Phylotype abundance and the Shannon 'H' diversity index were significantly higher in breast milk samples in the CD group. There was higher prevalence of the phyla Bacteroidetes and Fusobacteria, the classes Clostridia and Fusobacteriia, and the genera Leptotrichia, Anaerococcus, Sphingomonas, Actynomyces and Akkermansia in the CD group. The immunological markers were differently associated with some Gram-negative bacterial genera and species (Chryseobacterium, Sphingobium) as well as Gram-positive species (Lactobacillus reuteri, Bifidobacterium animalis). In conclusion, the microbiota in breast milk from mothers of genetically predisposed offspring who presented CD showed a higher bacterial phylotype abundance and diversity, as well as a different bacterial composition, as compared with the mothers of unaffected offspring. These immune markers showed some associations with bacterial composition and may influence the risk for development of CD beyond early childhood.

Interleukin-7, T helper 1, and regulatory T-cell activity-related cytokines are increased during the second trimester of healthy pregnancy compared to non-pregnant women.

PROBLEM: Healthy pregnancy is associated with a physiologic increase in inflammatory responses. The objective of this study was to assess changes in plasma cytokines associated with uncomplicated pregnancy. METHOD OF STUDY: To examine these changes, plasma levels of immune response mediators from healthy gravidas (N = 115, gestation weeks 23-30) were compared with those from healthy non-pregnant women (N = 42). Comparisons were performed using multiplex analysis for Th1 activity-related cytokines (IFN-γ, IL-2, sIL-2Rα, IL-12[P70], and IL-27), Th2 activity-related cytokines (IL-4, IL-5, and IL-13), other immune response mediators (GM-CSF, IL-1ß, sIL-1RI, IL-6, IL-8, IL-15, IL-17A, IL-17F, IL-21, IL-22, IL-23, TGFß1, TGFß2, TGFß3, and TNFα), regulatory T cell-related cytokines (IL-10 and sTNFRII), adipokines (adiponectin, leptin, PAI-1, and resistin), chemokines (IP-10, MCP-1, and MIP-1ß), and hematopoietic growth factor IL-7. RESULTS: Multivariate linear regression models showed increased levels of IL-7, Th1-, and Treg activity-related cytokines and decreased levels of adipokines and chemokines in healthy gravidas compared with healthy non-pregnant women. Additionally, season of the year, age, pre-pregnancy body mass index, and HLA-DR/DQ genotypes for type 1 diabetes risk showed different and sometimes reciprocal influence on cytokine levels. CONCLUSION: Our study stresses the importance of profiling immune response mediators during pregnancy to better understand the effect of healthy pregnancy on cytokine levels.

Celiac Disease in Children, Particularly with Accompanying Type 1 Diabetes, Is Characterized by Substantial Changes in the Blood Cytokine Balance, Which May Reflect Inflammatory Processes in the Small Intestinal Mucosa.

Cytokines play a pivotal role in the maintenance of intestinal homeostasis inducing pro- or anti-inflammatory response and mucosal barrier function in celiac disease (CD) and type 1 diabetes (T1D). We aimed to compare the levels of pro- and anti-inflammatory cytokines in CD patients without and with coexisting T1D, as well as to evaluate its association with the presence of enteroviruses (EV), regulatory T cells (Tregs), and dendritic cells (DCs) in small bowel mucosa. Altogether, 72 patients (median age 10.1 years) who had undergone small bowel biopsy were studied. The study group consisted of 24 patients with CD (median age 6.5 years), 9 patients with CD and concomitant T1D (median age 7.0 years), two patients with T1D (median age 8.5 years), and 37 patients (median age 14.0 years) with functional gastrointestinal disorders (FGD) and a normal small bowel mucosa as controls. The levels of 33 cytokines in serum were measured by multiple analysis using the Milliplex® MAP Magnetic Bead assay. The densities of FOXP3+ Tregs, CD11c+ DC, indoleamine 2,3-dioxygenase+ (IDO+) DC, langerin+ (CD207+) DCs, and EV were evaluated by immunohistochemistry as described in our previous studies. Circulating anti-EV IgA and IgG were evaluated using ELISA. The most important finding of the study is the significant increase of the serum levels of IL-5, IL-8, IL-13, IL-15, IL-17F, IL-22, IL-27, IP-10, MIP-1ß, sIL-2Rα, sTNFRII, and TNFα in CD patients compared to controls and its correlation with the degree of small bowel mucosa damage graded according to the Marsh classification. The leptin level was higher in females in all study groups. The levels of IL-2, IL-6, IL-12 (P70), IL-15, IP-10, and IFNγ correlated significantly with the density of FOXP3+ Tregs in lamina propria of the small bowel mucosa, which supports the evidence about the signaling role of these cytokines in the peripheral maintenance of FOXP3+ Tregs. At the same time, a significant negative correlation occurred between the level of IL-4 and density of FOXP3+ Tregs in controls. Another important finding of our study was the correlation of IL-17F, IP-10, sTNFRII, MCP-1, and GM-CSF with the density of EV-positive cells in the lamina propria of the small bowel mucosa. Correlation of MIP-1 (CCL-4) with CD103+ DC and langerin+ DC densities may point to their significance in the recruitment of immune cells into the lamina propria and in driving the inflammatory response in CD patients. Our results suggest the predominance of Th1 and Th17 immune responses over EV VP1 protein in CD and T1D patients. The significant elevation of Th2 cytokines, like IL-5 and IL-13, but not IL-4, in CD patients and its correlation with the degree of small bowel mucosa damage could reflect the role of these cytokines in gut defense and inflammation.

MicroRNA profiling of second trimester maternal plasma shows upregulation of miR-195-5p in patients with gestational diabetes.

Gestational diabetes (GDM) is defined as glucose intolerance that presents during pregnancy. It increases the risk of developing diabetes later in life. Recent studies indicate the important role of microRNAs (miRNAs) in the pathogenesis of diabetes, including GDM. However, information on the plasma miRNA profile in GDM patients at the late second trimester, at which time the glucose metabolism disorder manifests, is scarce. This study aimed to determine the plasma miRNA expression profiles of the pregnant women with GDM and compare them to those of pregnant controls using the real-time PCR array method. The study involved 22 single-pregnancy women (mean age ±â€¯standard deviation of 29.9 ±â€¯4.5 years old) who underwent a glucose tolerance test between 23 and 31 weeks of gestation. Of them, 13 were diagnosed with GDM. We identified 15 upregulated miRNAs in the GDM patients that were involved in 41 pathways. Among the top 10 associated pathways, fatty acid biosynthesis and fatty acid metabolism were targeted by the most, of the miRNAs investigated, with very low p values (p < 1e-325, false discovery rate corrected). MiR-195-5p, which targeted the highest number of genes important in metabolism, showed the highest fold upregulation. We conclude that increased miRNA expression, especially miR-195-5p, in plasma is characteristic of and causally related to the development of GDM.

Autoimmune activation toward embryo implantation is rare in immune-privileged human endometrium.

Human embryo implantation represents embryo apposition, adhesion to the endometrial epithelium, and invasion into the stromal extracellular matrix within 1 to 2 days during days 6 to 9 after ovulation. The major molecular mechanisms mediating implantation include adhesion molecules, including mucins, selectins, integrins, and cadherins; extracellular matrix components, such as laminins and collagens and their degrading enzymes; phospholipids and immune regulatory molecules, including prostaglandins, cytokines; and immunosuppressive molecules expressed by invasive trophoblasts and endometrial cells. Many of these molecules are the targets for autoimmune reactions in autoimmune diseases and cancer; however, the relevance of those in immune-mediated implantation failure has not been defined. In this review, we will describe the molecules involved in 2-day event of human embryo implantation, which may also be involved in immune system activation and subsequently cause immune-mediated implantation failure. We speculate that the data in the literature are limited concerning antiendometrial antibodies because the endometrium might be taken as an immune-privileged site that avoids autoimmune activation that might harm the implantation process. Antibodies affecting human fertility in ways other than impairing implantation are outside the scope of the current article and will not be discussed.